import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;
import org.omg.CORBA.PUBLIC_MEMBER;
import java.sql.Connection;
import javax.sql.DataSource;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBUtil {
    private static final String URL="jdbc:mysql://127.0.0.1:3306/java0307?characterEncoding=utf8&autoReconnect=true&failOverReadOnly=false";
    private static final String USERNAME="root";
    private static final String PASSWORD="2029889073";

    private volatile static DataSource dataSource=null;

    private static DataSource getDataSource(){
        if(dataSource==null){
            synchronized (DBUtil.class){
                if(dataSource==null){
                    dataSource= new MysqlDataSource();
                    ((MysqlDataSource)dataSource).setUrl(URL);
                    ((MysqlDataSource)dataSource).setUser(USERNAME);
                    ((MysqlDataSource)dataSource).setPassword(PASSWORD);

                }
            }
        }


        return dataSource;
    }

    public static Connection getConnection() throws SQLException {
        return  getDataSource().getConnection();
    }
    public static void close(Connection connection, PreparedStatement statement, ResultSet resultSet){
        if(resultSet!=null){
            try {
                resultSet.close();
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
        if(statement!=null){
            try {
                statement.close();
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
        if(connection!=null){
            try {
                connection.close();
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
    }
}
